By taking into consideration the flow and combustion characteristics of liquid ethanol in microscale flow,a reasonable simulation model is selected based on theoretical analysis for the numerical simulation of microscale laminar-flow diffusion cumbustion of liquid ethanol,and the effects of droplet radiation heat transfer and boundary slip on the simulation are analyzed with Fluent. The simulated results are then compared with the measured ones finding that the numerical simulation considering both the droplet radiation heat transfer and the boundary slip is more accurate.